Process Guidance Note 2/08(13) - GOV.UK

processes
Revised: July 2013
© Crown copyright 2013
You may re-use this information (not including logos) free of charge in any format or medium, under the terms of the Open Government Licence. To view this licence, visit www.nationalarchives.gov.uk/doc/open-government-licence/ or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or e-mail: [email protected] This document/publication is also available on our website at:
http://www.defra.gov.uk/environment/quality/industrial/las-regulations/guidance/
Any enquiries regarding this document/publication should be sent to us at: Atmosphere and Local Environment Defra Area 5F Ergon House Horseferry Road London SW1P 2AL
Email: [email protected]
PG2/08(13) i
Revision of the guidance
The electronic version of this publication is updated from time to time with new or
amended guidance. Table 0.1 is an index to the latest changes (minor amendments
are generally not listed).
Date of change
July 2013 Throughout Addition of colour coding to tables
PG2/08(13) ii
Revision of the guidance ................................................................................................... i 1. Introduction ................................................................................................................. 1
Legal basis .................................................................................................................... 1 Who is the guidance for? ............................................................................................... 2 Updating the guidance ................................................................................................... 2 Consultation .................................................................................................................. 3 Policy and procedures ................................................................................................... 3
2. Timetable for compliance and reviews ...................................................................... 4 Existing processes or activities ...................................................................................... 4 Permit reviews ............................................................................................................... 5
3. Activity description ..................................................................................................... 6 Regulations ................................................................................................................... 6
Potential releases .......................................................................................................... 7
Pollutants and sources .................................................................................................. 7 4. Emission limits, monitoring and other provisions ................................................... 8
Monitoring, investigating and reporting ........................................................................ 10 Information required by the regulator ........................................................................... 10 Visible emissions ......................................................................................................... 11 Emissions of odour ...................................................................................................... 12
Abnormal events.......................................................................................................... 12 Start up and shutdown ................................................................................................. 13
Continuous monitoring ................................................................................................. 13 Calibration and compliance monitoring ........................................................................ 14 Varying of monitoring frequency .................................................................................. 15
Monitoring of unabated releases ................................................................................. 16 Representative sampling ............................................................................................. 17
5. Control techniques .................................................................................................... 18
Summary of best available techniques ........................................................................ 18 Techniques to control emissions from contained sources ........................................... 19 Fugitive emissions ....................................................................................................... 20 Air quality ..................................................................................................................... 21 Dispersion & dilution .................................................................................................... 21
Ambient air quality management ................................................................................. 21 Stacks, vents and process exhausts ........................................................................... 22 Management ............................................................................................................... 23 Management techniques ............................................................................................. 23 Appropriate management systems .............................................................................. 23
Training ....................................................................................................................... 24 Maintenance ................................................................................................................ 24
7. Further information ................................................................................................... 26 Sustainable consumption and production (SCP) ......................................................... 26 Health and safety......................................................................................................... 26 Further advice on responding to incidents ................................................................... 27
PG2/08(13) iii
List of Tables Table 0.1 - Revision of the guidance .................................................................................... i Table 2.1 - Compliance timetable ........................................................................................ 4 Table 3.1 - Regulations listing activities ............................................................................... 6
Table 4.1 - Emission limits, monitoring and other provisions ............................................... 9 Table 5.1 - Summary of control techniques ....................................................................... 18 Table 6.1 - Summary of changes ....................................................................................... 25
PG2/08(13) 1
1. Introduction
Legal basis
1.1 This note applies to the whole of the UK. It is issued by the Secretary of State, the
Welsh Government, the Scottish Government and the Department of the
Environment in Northern Ireland (DoE NI) to give guidance on the conditions
appropriate for the control of emissions into the air from copper and copper alloy
processes. It is published only in electronic form and can be found on the Defra
website. It supersedes PG2/07(04) and NIPG2/07(04).
1.2 This guidance document is compliant with the Code of Practice on Guidance on
Regulation page 6 of which contains the "golden rules of good guidance". If you feel
this guidance breaches the code or you notice any inaccuracies within the
guidance, please contact us.
1.3 This is one of a series of statutory notes giving guidance on the Best Available
Techniques (BAT). The notes are all aimed at providing a strong framework for
consistent and transparent regulation of installations regulated under the statutory
Local Air Pollution Prevention and Control (LAPPC) regime in England and Wales,
Scotland and Northern Ireland. The note will be treated as one of the material
considerations when determining any appeals against a decision made under this
legislation. Further guidance on the meaning of BAT can be found for England and
Wales (in chapter 12 of the General Guidance Manual), Scotland, and Northern
Ireland, (in chapter 9).
1.4 In general terms, what are BAT for one installation in a sector are likely to be BAT
for a comparable installation. Consistency is important where circumstances are the
same. However, in each case it is, in practice, for regulators (subject to appeal) to
decide what are BAT for each individual installation, taking into account variable
factors such as the configuration, size and other individual characteristics of the
installation, as well as the locality (e.g. proximity to particularly sensitive receptors).
1.5 The note also, where appropriate, gives details of any mandatory requirements
affecting air emissions which are in force at the time of publication, such as those
contained in Regulations or in Directions from the Government. In the case of this
note, at the time of publication there were no such mandatory requirements.
PG2/08(13) 2
1.6 In Section 4 and Section 5, arrows are used to indicate the matters which should
be considered for inclusion as permit conditions. It is important to note, however,
that this should not be taken as a short cut for regulators to a proper determination
of BAT or to disregard the explanatory material which accompanies the arrows. In
individual cases it may be justified to:
include additional conditions;
include different conditions;
not include conditions relating to some of the matters indicated.
In addition, conditions will need to be derived from other parts of the note, in
particular to specify emission limits, compliance deadlines and mandatory
requirements arising from directions or other legislation.
Who is the guidance for?
1.7 This guidance is for:
Regulators
local authorities in England and Wales, who must have regard to this statutory guidance when determining applications for permits and reviewing extant permits;
the Scottish Environment Protection Agency (SEPA) in Scotland, and district councils or the Northern Ireland Environment Agency (NIEA), in Northern Ireland;
Operators who are best advised also to have regard to it when making applications
and in the subsequent operation of their installation;
Members of the public who may be interested to know what the Government
considers, in accordance with the legislation, amounts to appropriate conditions for
controlling air emissions for the generality of installations in this particular industry
sector.
Updating the guidance
1.8 The guidance is based on the state of knowledge and understanding, at the time of
writing, of what constitute BAT for this sector. The note may be amended from time
to time to keep up with developments in BAT, including improvements in
techniques, changes to the economic parameters, and new understanding of
environmental impacts and risks. The updated version will replace the previous
version on the Defra website and will include an index to the amendments.
PG2/08(13) 3
1.9 Reasonable steps will be taken to keep the guidance up-to-date to ensure that
those who need to know about changes to the guidance are informed of any
published revisions. However, because there can be rapid changes to matters
referred to in the guidance – for example to legislation – it should not be assumed
that the most recent version of this note reflects the very latest legal requirements;
these requirements apply.
Consultation
1.10 This note has been produced in consultation with relevant trade bodies,
representatives of regulators including members of the Industrial Pollution Liaison
Committee and other potentially-interested organisations.
Policy and procedures
1.11 General guidance explaining LAPPC and setting out the policy and procedures is
contained in separate documents for England and Wales, Scotland and Northern
Existing processes or activities
2.1 This note contains all the provisions from previous editions which have not been
removed. Some have been amended. For installations in operation at the date this
note is published, the regulator should have already issued or varied the permit
having regard to the previous editions. If they have not done so, this should now be
done.
2.2 The new provisions of this note and the dates by which compliance with these
provisions is expected are listed in Table 2.1, together with the paragraph number
where the provision is to be found. Compliance with the new provisions should
normally be achieved by the dates shown. Permits should be varied as necessary,
having regard to the changes and the timetable.
Table 2.1 - Compliance timetable
Compliance date
There are no new provisions in this note likely of themselves to result in a need to vary existing permit conditions. For a full list of changes made by this note, excluding very minor ones, see Table 6.1.
2.3 Replacement plant should normally be designed to meet the appropriate standards
specified for new installations/activities.
2.4 Where provisions in the preceding guidance note have been deleted or relaxed,
permits should be varied as necessary as soon as reasonably practicable.
2.5 For new activities, the permit should have regard to the full standards of this
guidance from the first day of operation.
2.6 For substantially changed activities, the permit should normally have regard to the
full standards of this guidance with respect to the parts of the activity that have been
substantially changed and any part of the activity affected by the change, from the
first day of operation.
PG2/08(13) 5
Permit reviews
2.7 Under LAPPC, the legislation requires permits to be reviewed periodically but does
not specify a frequency. It is considered for this sector that a frequency of once
every eight years ought normally to be sufficient for the purposes of the appropriate
Regulations. Further guidance on permit reviews is contained in the appropriate
Guidance Manual for England and Wales, Scotland, Practical guide section 10 and
Northern Ireland Part B Guidance page 9, Northern Ireland Part C Guidance
chapter 17. Regulators should use any opportunities to determine the variations to
permits necessitated by paragraph 2.2 above in conjunction with these reviews.
2.8 Conditions should also be reviewed where complaint is attributable to the operation
of the process and is, in the opinion of the regulator, justified.
Regulations
3.1 This note applies to LAPPC installations for the copper and copper alloy processes.
The activities for regulation are listed in Table 3.1.
Table 3.1 - Regulations listing activities
LAPPC England and Wales Scotland Northern Ireland
EPR Schedule 1 reference
PPC Schedule 1 reference
PPC Schedule 1 reference
Part B Section 2.2 Part B Section 2.2, Part B Section 2.2 Part B
Part C n/a n/a Section 2.2 Part C
The links are to the original version of the Regulations. A consolidated version is not available on www.legislation.gov.uk.
3.2 This note refers to processes melting copper or copper alloys, in an installation with
a melting capacity of 20 tonnes or less per day.
3.3 Auxiliary foundry operations including casting and finishing are the subject of
another note PG2/04 and processes for the thermal segregation and recovery or
extraction of copper from mixed scrap are the subject of another note PG2/01.
3.4 Processes where non-ferrous metal is produced from secondary raw materials are
included in Part A of the definition under LAPPC.
3.5 Refining which is incidental to the process of making or melting copper or copper
alloys is, however, covered in this note. Such metal treatment processes include
compositional adjustment and degassing using nitrogen (though this is not a
common activity).
For the purpose of this note, refining is defined as "to cleanse, reduce or remove
deleterious elements, oxides or other gangue material, for example by means of the
addition of salt flux or the injection of gases to the molten metal".
3.6 Typically these processes use electrical induction, gas or oil fired crucible furnaces.
Metal melted is either ingot or clean returns or clean scrap to produce a wide range
of alloys. Casting may be batch or continuous.
Pollutants and sources
3.7 The key emissions from these processes are those consisting of particulate matter,
inorganic chloride and fluoride, and metals (depending upon the alloys melted) such
as copper, zinc, lead, nickel, tin and their compounds.
3.8 Use of chloride fluxes will give rise to chloride emissions.
3.9 Use of fluoride fluxes will give rise to fluoride emissions.
3.10 Handling of raw materials and residues may give rise to particulate matter in the
form of dust.
3.11 The melting of metal may give rise to metals emitted mainly in the form of oxide
fume (particulate fraction). The metal compounds emitted will depend upon the
make up of the feedstock. Alloys that contain zinc will have a greater emission due
to the low boiling point of zinc, which is released as zinc oxide.
3.12 Dioxins may be produced if the conditions that give rise to such pollutants are
present. These are:
presence of chloride ions - these can arise from scrap that is contaminated with chlorine containing plastics or chlorinated cutting fluids, from use of coal, coke, fuel oil and from certain fluxes.
presence of organic carbon - this may arise from organic contaminants in scrap and from coal, coke or oil used as fuel.
gases held between 200°C and 650°C especially in the presence of a metal catalyst such as copper.
PG2/08(13) 8
4. Emission limits, monitoring and other provisions
4.1 Emissions of the substances listed in Table 4.1 should be controlled.
4.2 The emission limit values and provisions described in this section are achievable
using the best available techniques described in Section 5. Monitoring of
emissions should be carried out according to the method specified in this section or
by an equivalent method agreed by the regulator. Where reference is made to a
British, European, or International standard (BS, CEN or ISO) in this section, the
standards referred to are correct at the date of publication. (Users of this note
should bear in mind that the standards are periodically amended, updated or
replaced.) The latest information regarding the monitoring standards applicable can
be found at the Source Testing Association website. Further information on
monitoring can be found in Environment Agency publications, M1 and M2.
4.3 All activities should comply with the emission limits and provisions with regard to
releases in Table 4.1.
The reference conditions for limits in Section 4 are: 273.1K, 101.3kPa, without
correction for water vapour content, unless stated otherwise.
Table 4.1 should be considered in conjunction with the monitoring paragraphs
found later in this section.
Row Substance Source Emission limits/provisions
Type of monitoring Monitoring frequency
1 Total particulate matter Melting, holding and pouring processes*
20 mg/m3 Indicative Continuous
2 Total particulate matter Other processes e.g. fettling, grinding, shot blasting*
20 mg/m3 Indicative Continuous
20 mg/m3 Manual extractive test Annual
4 Lead and lead compounds (expressed as lead)
From melting and holding furnaces and from pouring
5 Nickel and nickel compounds (expressed as nickel)
6 Tin and tin com pounds (expressed as tin)
7 Cadmium, chromium and their compounds (expressed as the metal)
Total emission in combination 1 mg/m3
Manual extractive test Annual
8 Chloride (expressed as hydrogen chloride)
Processes where chloride fluxes are used
9 Fluoride (expressed as hydrogen fluoride)
Processes where fluoride fluxes are used
10 Dioxins Processes likely to emit dioxins 1 ng/m3 (I- TEQ) Manual extractive test Annual
*Certain alloys give rise to negligible particulate emissions as they do not contain zinc or lead, and extraction and monitoring is not applicable to processes melting these alloys. If other alloys make up more than 2% of the total melted in any twelve month period then the limits should apply.
PG2/08(13) 10
Monitoring, investigating and reporting
4.4 The operator should monitor emissions, make tests and inspections of the activity.
The need for and scope of testing (including the frequency and time of sampling)
will depend on local circumstances.
The operator should keep records of inspections, tests and monitoring,
including all non-continuous monitoring, inspections and visual assessments.
Records should be:
kept on site;
kept by the operator for at least two years; and
made available for the regulator to examine.
If any records are kept off-site they should be made available for inspection
within one working week of any request by the regulator.
Information required by the regulator
4.5 The regulator needs to be informed of monitoring to be carried out and the results.
The results should include process conditions at the time of monitoring.
The operator should notify the regulator at least 7 days before any periodic
monitoring exercise to determine compliance with emission limit values. The
operator should state the provisional time and date of monitoring, pollutants to
be tested and the methods to be used.
The results of non-continuous emission testing should be forwarded to the
regulator within 8 weeks of completion of the sampling.
Adverse results from any monitoring activity (both continuous and non-
continuous) should be investigated by the operator as soon as the monitoring
data has been obtained. The operator should:
identify the cause and take corrective action;
clearly record as much detail as possible regarding the cause and extent of the problem, and the remedial action taken;
re-test to demonstrate compliance as soon as possible; and inform the regulator of the steps taken and the re-test results.
PG2/08(13) 11
Visible emissions
4.6 The aim should be to prevent any visible airborne emission from any part of the
process. This aim includes all sites regardless of location. Monitoring to identify the
origin of a visible emission should be undertaken and a variety of indicative
techniques are available.
where ambient monitoring is carried out it may also be appropriate for the regulator to specify recording of wind direction and strength;
where combustion units are in use for dryers then the combustion process should be controlled and equipment maintained as appropriate.
4.7 Emissions from combustion processes in normal operation should be free from
visible smoke. During start up and shut down the emissions should not exceed the
equivalent of Ringelmann Shade 1 as described in British Standard BS 2742.
All other releases to air, other than condensed water vapour, should be free
from persistent visible emissions.
All emissions to air should be free from droplets.
Where there are problems that, in the opinion of the regulator, may be attributable
to the installation, such as local complaints of visual emissions or where dust from
the installation is being detected beyond the site boundary, the operator should
investigate in order to find out which part of their operation(s) is the cause.
If this inspection does not lead to correction of the problem then the operator should
inform the regulator who will determine whether ambient air monitoring is
necessary. Ambient monitoring may either be by a British Standard method or by a
method agreed with the regulator.
Whilst problems are ongoing, a visual check should also be made at least once per
day/shift, by the operator, when an installation is being operated. The time, location
and result of these checks, along with weather conditions such as indicative wind
direction and strength, should be recorded. Once the source of the emission is
known, corrective action should be taken without delay and where appropriate the
regulator may want to vary the permit in order to add a condition requiring the
particular measure(s) to be undertaken.
PG2/08(13) 12
Emissions of odour
4.8 The overall aim should be that all emissions are free from offensive odour outside
the site boundary, as perceived by the regulator. However, the location of the
installation will influence the assessment of the potential for odour impact as local
meteorological conditions may lead to poor dispersion conditions. Where the site
has a low odour impact due to its remoteness from sensitive receptors, the escape
of offensive odour beyond the installation would be unlikely to cause harm.
4.9 Where there are problems that, in the opinion of the regulator, may be attributable
to the installation, such as local complaints of odour or where odour from the
installation is being detected beyond the site boundary, the operator should
investigate in order to find out which part of their operation(s) is the cause.
4.10 Whilst problems are ongoing, a boundary check should also be made at least once
per day/shift, by the operator, when an installation is being operated. The time,
location and result of these checks, along with weather conditions such as indicative
wind direction and strength, should be recorded. Once the source of the emission
is known, corrective action should be taken without delay and where appropriate the
regulator may want to vary the permit in order to add a condition requiring the
particular measure(s) to be undertaken.
Abnormal events
4.11 The operator should respond to problems which may have an adverse effect on
emissions to air.
In the case of abnormal emissions, malfunction or breakdown leading to
abnormal emissions the operator should:
investigate and undertake remedial action immediately;
adjust the process or activity to minimise those emissions; and
promptly record the events and actions taken.
The regulator should be informed without delay, whether or not there is related
monitoring showing an adverse result:
if there is an emission that is likely to have an effect on the local community; or
in the event of the failure of key arrestment plant, for example, bag filtration plant or scrubber units.
The operator should provide a list of key arrestment plant and should have a
written procedure for dealing with its failure, in order to minimise any adverse
effects.
Start up and shutdown
4.12 Higher emissions may occur during start-up and shut-down of a process. These
emissions can be reduced, by minimising, where possible, the number of start-ups
and shut-downs and having adequate procedures in place for start-up, shut-down
and emergency shut-downs.
The number of start-ups and shut downs should be kept to the minimum that is
reasonably practicable.
All appropriate precautions must be taken to minimise emissions during start-
up and shutdown.
4.13 Continuous monitoring can be either „quantitative or „indicative. With quantitative
monitoring the discharge of the pollutant(s) of concern is measured and recorded
numerically. For pollution control this measurement is normally expressed in
milligrams per cubic metre of air (mg/m3). Where discharge of the pollutant
concerned is controlled by measuring an alternative parameter (the „surrogate
measurement), this surrogate is also expressed numerically.
Continuous indicative monitoring is where a permanent device is fitted, for example,
to detect leaks in a bag filter, but the output, whether expressed numerically or not,
does not show the true value of the discharge. When connected to a continuous
recorder it will show that emissions are gradually (or rapidly) increasing, and
therefore maintenance is required. Alternatively it can trigger an alarm when there is
a sudden increase in emissions, such as when arrestment plant has failed.
4.14 Where continuous indicative monitoring has been specified, the information
provided should be used as a management tool. Where used, the monitor should
be set up to provide a baseline output when the plant is known to be operating
under the best possible conditions and emissions are complying with the
requirements of the permit. Where used to trigger alarms, the instrument
manufacturer should be able to set an output level which corresponds to around
75% of the emission limit. Thus the alarms are activated in response to this
significant increase in pollutant loading above the baseline, so that warning of the
changed state is given before an unacceptable emission occurs. The regulator may
wish to agree the alarm trigger level.
PG2/08(13) 14
4.15 Where continuous monitoring is required, it should be carried out as follows:
All continuous monitoring readings should be on display to appropriately
trained operating staff.
Instruments should be fitted with audible and visual alarms, situated
appropriately to warn the operator of arrestment plant failure or malfunction.
The activation of alarms should be automatically recorded.
All continuous monitors should be operated, maintained and calibrated (or
referenced, in the case of indicative monitors) in accordance with the
manufacturers instructions, which should be made available for inspection by
the regulator.
The relevant maintenance and calibration (or referencing, in the case of
indicative monitors) should be recorded.
Emission concentrations may be reported as zero when the plant is off and
there is no flow from the stack. If required a competent person should confirm
that zero is more appropriate than the measured stack concentration if there is
no flow.
Any continuous monitor used should provide reliable data >95% of the
operating time, (i.e. availability >95%). A manual or automatic procedure
should be in place to detect instrument malfunction and to monitor instrument
availability.
Calibration and compliance monitoring
4.16 Compliance monitoring can be carried out either by use of a continuous emissions
monitor (CEM), or by a specific extractive test carried out at a frequency agreed
with the regulator.
4.17 Where a CEM is used for compliance purposes it must be periodically checked,
(calibrated), to ensure the readings being reported are correct. This calibration is
normally done by carrying out a parallel stand-alone extractive test and comparing
the results with those provided by the CEM.
4.18 For extractive testing the sampling should meet the following requirements:
For batch processes, where the production operation is complete within, say, 2
hours, then the extractive sampling should take place over a complete cycle of
the activity.
PG2/08(13) 15
4.19 Should the activity either be continuous, or have a batch cycle that is not compatible
with the time available for sampling, then the data required should be obtained over
a minimum period of 2 hours in total.
For demonstration of compliance where a CEM is used no daily mean of all
15-minute mean emission concentrations should exceed the specified
emission concentration limits during normal operation (excluding start-up and
shut-down); and
No 15-minute mean emission concentration should exceed twice the specified
emission concentration limits during normal operation (excluding start-up and
shut-down).
For extractive testing, no result of monitoring should exceed the emission limit
concentrations specified.
4.20 Exhaust flow rates should be consistent with efficient capture of emissions, good
operating practice and meeting the requirements of the legislation relating to the
workplace environment.
The introduction of dilution air to achieve emission concentration limits should
not be permitted.
Dilution air may be added for waste gas cooling or improved dispersion where this
is shown to be necessary because of the operational requirements of the plant, but
this additional air should be discounted when determining the mass concentration of
the pollutant in the waste gases.
Varying of monitoring frequency
4.21 Where non-continuous quantitative monitoring is required, the frequency may be
varied. Where there is consistent compliance with emission limits, regulators may
consider reducing the frequency. However, any significant process changes that
might have affected the monitored emission should be taken into account in making
the decision.
PG2/08(13) 16
4.22 When determining “consistent compliance” the following are cases which might not
qualify for a reduction in monitoring:
a) variability of results: cases where monitoring results vary widely and include
results in the range 12-18mg/m3 (when the emission limit is 20mg/m3)
b) the margin between the results and the emission limit: cases where results
over a period are 18mg/m3 or more (when the emission limit is 20mg/m3).
Consistent compliance should be demonstrated using the results from at least;
three or more consecutive annual monitoring campaigns; or
two or more consecutive annual monitoring campaigns supported by continuous monitoring.
Where a new or substantially changed process is being commissioned, or where
emission levels are near to or approach the emission concentration limits,
regulators should consider increasing the frequency of testing.
4.23 A reduction in monitoring frequency should not be permitted where continuous
quantitative or indicative monitoring is required. These types of monitoring are
needed to demonstrate at all times when the plant is operating, that either the
emission limits are being complied with or that the arrestment equipment is
functioning correctly.
Monitoring of unabated releases
4.24 Where emission limit values are consistently met without the use of abatement
equipment, the monitoring requirement for those pollutants should be dispensed
with subject to the “Varying of monitoring frequency” paragraphs above.
Where monitoring is not in accordance with the main procedural requirements of the
relevant standard, deviations should be reported as well as an estimation of any
error invoked.
PG2/08(13) 17
Representative sampling
4.25 Whether sampling on a continuous or non-continuous basis, care is needed in the
design and location of sampling systems, in order to obtain representative samples
for all release points.
Sampling points on new plant should be designed to comply with the British or
equivalent standards (see paragraph 4.2).
The operator should ensure that relevant stacks or ducts are fitted with
facilities for sampling which allow compliance with the sampling standards.
Where monitoring is not in accordance with the main procedural requirements of the
relevant standard, deviations should be reported.
PG2/08(13) 18
Summary of best available techniques
5.1 Table 5.1 provides a summary of the best available techniques that can be used to
control the process in order to meet the emission limits and provisions in Section 4.
Provided that it is demonstrated to the satisfaction of the regulator that an
equivalent level of control will be achieved, then other techniques may be used.
Table 5.1 - Summary of control techniques
Release source Substance Control techniques
Melting and holding furnaces
Control furnace temperature - superheat provision varies according to process (e.g. continuous or batch casting), but should be kept as low as possible.
Contain emissions - by enclosed furnace for example:
Extract emissions.
Good combustion.
Particle arrestment.
Dry filter arrestment plant Particulate matter Ensure management of dust collected - collect directly into container for disposal to eliminate double handling, ensure collection vessels are secured and sealed.
Dross Particulate matter Collect dross into designated containers or bays. Keep it dry and store under cover.
PG2/08(13) 19
5.2 Operational controls are the primary method of minimising emissions:
Different alloys require different temperatures on pouring of the metal. If the
metal temperature is not adequately controlled then excessive fuming can
result, particularly where zinc containing alloys are being produced. A dip
pyrometer is usually used to measure melt temperatures in the furnace.
The addition of flux to both melting and holding furnaces should be minimised
as far as possible, consistent with good operating practice.
Further to operational controls, containment and arrestment of emissions may
be necessary. The use of enclosed furnaces, peripheral lip extraction or fume
collection enclosures with extract ventilation are commonly used techniques.
Enclosed furnaces, casings, ductwork and ancillary equipment should be
made and maintained as gas tight as is practicable. Filtered particulate
emissions can be expected to be below 10 mg/m3 if modern plant designed for
the purpose is used.
Where scrap material is melted, care should be taken in selection of scrap and
its introduction into the furnace to prevent emissions.
A scrap quality control system should be in place to ensure that unsuitable
scrap is not melted.
Furnaces should be fitted with temperature controls to ensure that melting
temperatures are kept as low as possible, so as to minimise emissions of
fume. The melt temperature should be measured frequently and at least once
during each melt when the potential for fume generation is greatest, such as
before pouring.
Emissions should be vented to suitable arrestment plant where necessary to
meet the provisions of this note.
Where practicable in relation to plant configuration, emissions produced during
pouring should be contained by the use of secondary fume collection
ventilation such as a hood or lip extraction which are commonly used
techniques. This should vent to suitable arrestment plant where necessary to
meet the provisions of this note.
Where provided, furnace doors or lids should be kept closed except for a
minimum period during charging of the furnace or during working of the metal.
PG2/08(13) 20
Fugitive emissions
5.3 Emissions from the melting operations covered by this note comprise very fine
particulate matter. The control of fugitive emissions from these processes is mainly
by the use of containment, extraction and arrestment to achieve the provisions
described in Table 4.1. Extraction systems should be designed, in particular, to
deal with those operations which are likely to generate excessive or fugitive
emissions, for example charging of the furnace.
All process buildings should be cleaned regularly to minimise the risk of
fugitive emissions and made as dust tight as is necessary to prevent visible
emissions.
Where local exhaust ventilation is used, emissions should be ducted to
suitable arrestment plant, if necessary to achieve the provisions of this note.
The method of collection and disposal of product or waste from dry arrestment
plant should be such that dust emissions are minimised.
Adequate provision should be made for the containment of liquid and solid
spillages. All spillages should be cleared as soon as possible and in the case
of solid materials this should be achieved by the use of vacuum cleaning, wet
methods, or other appropriate techniques. All process buildings should be
cleaned regularly to minimise the risk of fugitive emissions.
Stocks of dusty, or potentially dusty, materials for example dross and fluxing
powders should be stored in such a manner as to minimise wind whipping.
Loading to and from stockpiles should be carried out in a manner which will
minimise emissions to the air.
All residues produced, including those produced by arrestment plant, should
be handled and stored in a manner which minimises emissions to the air. Such
materials should be handled under dry conditions and stored in clearly
designated bays or containers after cooling.
Dusty wastes should be stored in closed containers.
All spillages should be cleared as soon as possible; solids by vacuum
cleaning, wet methods, or other appropriate techniques.
A high standard of housekeeping should be maintained.
PG2/08(13) 21
Air quality
Dispersion & dilution
5.4 Pollutants that are emitted via a stack require sufficient dispersion and dilution in the
atmosphere to ensure that they ground at concentrations that are deemed
harmless. This is the basis upon which stack heights are calculated using HMIP
Technical Guidance Note (Dispersion) D1. The stack height so obtained is adjusted
to take into account local meteorological data, local topography, nearby emissions
and the influence of plant structure.
The calculation procedure of D1 is usually used to calculate the required stack
height but alternative dispersion models may be used in agreement with the
regulator. An operator may choose to meet tighter emission limits in order to reduce
the required stack height.
5.5 Where an emission consists purely of air and particulate matter, (i.e. no products of
combustion or any other gaseous pollutants are emitted) the above provisions
relating to stack height calculation for the purpose of dispersion and dilution should
not normally be applied. Revised stack height calculations should not be required as
a result of publication of this revision of the PG note, unless it is considered
necessary because of a breach or serious risk of breach of an EC Directive limit
value or because it is clear from the detailed review and assessment work that the
permitted process itself is a significant contributor to the problem.
Ambient air quality management
5.6 In areas where air quality standards or objectives are being breached or are in
serious risk of breach and it is clear from the detailed review and assessment work
under Local Air Quality Management that the permitted process itself is a significant
contributor to the problem, it may be necessary to impose tighter emission limits. If
the standard that is in danger of being exceeded is not an EC Directive requirement,
then industry is not expected to go beyond BAT to meet it. Decisions should be
taken in the context of a local authoritys Local Air Quality Management action plan.
For example, where a permitted process is only responsible to a very small extent
for an air quality problem, the authority should not unduly penalise the operator of
the process by requiring disproportionate emissions reductions.
PG2/08(13) 22
Paragraph 59 of the Air Quality Strategy 2007 [Volume 1] gives the following advice:
“...In drawing up action plans, local authority environmental health/pollution teams
are expected to engage local authority officers across different departments,
particularly, land-use and transport planners to ensure the actions are supported by
all parts of the authority. In addition, engagement with the wider panorama of
relevant stakeholders, including the public, is required to ensure action plans are fit-
for-purpose in addressing air quality issues. It is vital that all those organisations,
groups and individuals that have an impact upon local air quality, buy-in and work
towards objectives of an adopted action plan.”
Stacks, vents and process exhausts
5.7 Liquid condensation on internal surfaces of stacks and exhaust ducts might lead to
corrosion and ductwork failure or to droplet emission. Adequate insulation will
minimise the cooling of waste gases and prevent liquid condensation by keeping the
temperature of the exhaust gases above the dewpoint. A leak in a stack/vent and
the associated ductwork, or a build up of material on the internal surfaces may
affect dispersion:
Flues and ductwork should be cleaned to prevent accumulation of materials,
as part of the routine maintenance programme.
5.8 When dispersion of pollutants discharged from the stack (or vent) is necessary, the
target exit velocity should be 15m/s under normal operating conditions, (but see
paragraph below regarding wet plumes). In order to ensure dispersion is not
impaired by either low exit velocity at the point of discharge, or deflection of the
discharge, a cap, or other restriction, should not be used at the stack exit.
However, a cone may sometimes be useful to increase the exit velocity to achieve
greater dispersion.
5.9 An exception to the above is where wet arrestment is used as the abatement.
Unacceptable emissions of droplets could occur from such plant where the linear
velocity in the stack exceeds 9m/s.
5.10 To reduce the potential of droplet emissions a mist eliminator should be used.
Where a linear velocity of 9m/sec is exceeded in existing plant consideration should
be given to reducing this velocity as far as practicable to ensure such droplet
entrainment and fall out does not happen.
proper management, supervision and training for process operations;
proper use of equipment;
effective preventative maintenance on all plant and equipment concerned with the control of emissions to the air; and
ensuring that spares and consumables - in particular, those subject to continual wear – are held on site, or available at short notice from guaranteed local suppliers, so that plant breakdowns can be rectified rapidly. This is important with respect to arrestment plant and other necessary environmental controls. It is useful to have an audited list of essential items.
Appropriate management systems
5.12 Effective management is central to environmental performance; it is an important
component of BAT and of achieving compliance with permit conditions. It requires a
commitment to establishing objectives, setting targets, measuring progress and
revising the objectives according to results. This includes managing risks under
normal operating conditions and in accidents and emergencies.
It is therefore desirable that installations put in place some form of structured
environmental management approach, whether by adopting published standards
(ISO 14001 or the EU Eco Management and Audit Scheme [EMAS]) or by setting
up an environmental management system (EMS) tailored to the nature and size of
the particular process. Operators may also find that an EMS will help identify
business savings.
5.13 Regulators should use their discretion, in consultation with individual operators, in
agreeing the appropriate level of environmental management. Simple systems
which ensure that LAPPC considerations are taken account of in the day-to-day
running of a process may well suffice, especially for small and medium-sized
enterprises. Regulators are urged to encourage operators to have an EMS for all
their activities, but it is outside the legal scope of an LAPPC permit to require an
EMS for purposes other than LAPPC compliance. For further information/advice on
EMS refer to the appropriate chapter of the appropriate Guidance Manual for
England and Wales, Scotland and Northern Ireland.
Training
5.14 Staff at all levels need the necessary training and instruction in their duties relating
to control of the process and emissions to air. In order to minimise risk of emissions,
particular emphasis should be given to control procedures during start-up, shut
down and abnormal conditions. Training may often sensibly be addressed in the
EMS referred to above.
All staff whose functions could impact on air emissions from the activity should
receive appropriate training on those functions. This should include:
awareness of their responsibilities under the permit;
steps that are necessary to minimise emissions during start-up and shutdown;
actions to take when there are abnormal conditions, or accidents or spillages that could, if not controlled, result in emissions.
The operator should maintain a statement of training requirements for each
post with the above mentioned functions and keep a record of the training
received by each person. These documents should be made available to the
regulator on request.
Maintenance
5.15 Effective preventative maintenance plays a key part in achieving compliance with
emission limits and other provisions. All aspects of the process including all plant,
buildings and the equipment concerned with the control of emissions to air should
be properly maintained. In particular:
The operator should have the following available for inspection by the
regulator:
a written maintenance programme for all pollution control equipment; and
a record of maintenance that has been undertaken.
PG2/08(13) 25
6. Summary of changes
The main changes to this note, with the reasons for the change, are summarised in
Table 6.1. Minor changes that will not impact on the permit conditions e.g. slight
alterations to the Process Description have not been recorded.
Table 6.1 - Summary of changes
Section/
paragraph/
row
Removes need for extensive footnotes/references.
PG2/08(13) 26
Both business and the environment can benefit from adopting sustainable
consumption and production practices. Estimates of potential business savings
include:
£6.4 billion a year UK business savings from resource efficiency measures that cost little or nothing;
2% of annual profit lost through inefficient management of energy, water and waste;
4% of turnover is spent on waste.
When making arrangement to comply with permit conditions, operators are strongly
advised to use the opportunity to look into what other steps they may be able to
take, for example, having regard to the efficient use of auxiliary fuels, such as gas
and electricity. Regulators may be willing to provide assistance and ideas, although
cannot be expected to act as unpaid consultants.
Health and safety
Operators of installations must protect people at work as well as the environment:
requirements of a permit should not put at risk the health, safety or welfare of people at work or those who may be harmed by the work activity;
equally, the permit must not contain conditions whose only purpose is to secure the health of people at work. That is the job of the health and safety enforcing authorities.
Where emission limits quoted in this guidance conflict with health and safety limits,
the tighter limit should prevail because:
emission limits under the relevant environmental legislation relate to the concentration of pollutant released into the air from prescribed activities;
exposure limits under health and safety legislation relate to the concentration of pollutant in the air breathed by workers;
these limits may differ since they are set according to different criteria. It will normally be quite appropriate to have different standards for the same pollutant, but in some cases they may be in conflict (for example, where air discharged from a process is breathed by workers). In such cases, the tighter limit should be applied to prevent a relaxation of control.
PG2/08(13) 27
Further advice on responding to incidents
The UK Environment Agencies have published guidance on producing an incident
response plan to deal with environmental incidents. Only those aspects relating to
air emissions can be subject to regulation via a Part B (Part C in NI) permit, but
regulators may nonetheless wish to informally draw the attention of all appropriate
operators to the guidance.
It is not envisaged that regulators will often want to include conditions, in addition to
those advised in this PG note, specifying particular incident response arrangements
aimed at minimising air emissions. Regulators should decide this on a case-by-
case basis. In accordance with BAT, any such conditions should be proportionate
to the risk, including the potential for harm from air emissions if an incident were to
occur. Account should therefore be taken of matters such as the amount and type
of materials held on site which might be affected by an incident, the likelihood of an
incident occurring, the sensitivity of the location of the installation, and the cost of
producing any plans and taking any additional measures.

Process Guidance Note 2/08(13) - GOV.UK

Documents

Transcript of Process Guidance Note 2/08(13) - GOV.UK